Illustration by Pamela Colman Smith, 1910. Public domain in the US since 1966 and in the UK since 2021. Vector digitisation of the Rider–Waite–Smith deck by OpenClipart contributor "klaatu-tarot", released public domain.
Three of Pentacles
The Master Builder
In 1911 Waite identified the Three's sculptor with the Eight of Pentacles' apprentice, now rewarded and working in earnest.
A. E. Waite, The Pictorial Key to the Tarot (1911), Part III, section 2, Pentacles: Three; Global Grey 2017 transcription.
A mason stands on a bench in a church arch while a monk and a man holding plans consult him.
More context
A craftsman stands on a bench within a stone arch while two robed figures look towards the work. Waite's 1911 text calls him a sculptor in a monastery and explicitly compares him with the apprentice or amateur in the Eight of Pentacles. That worker has received a reward and now works in earnest. The divinatory list includes trade and skilled labour, but also nobility, aristocracy, renown and glory. Reversed meanings include mediocrity, pettiness and weakness, rather than a specific failure of teamwork.
Light
Waite gives skilled labour, trade, renown and glory, and presents a worker who has advanced beyond apprenticeship.
Shadow
His reversed list names mediocrity, puerility, pettiness and weakness, including weakness in the work itself.